In 2001, Hart was appointed Archbishop of Melbourne, replacing George Pell who became the Archbishop of Sydney. On 29 June 2001, he received the pallium from Pope John Paul II in St Peter's Square. Within the Australian Catholic Bishops Conference, he was a member of the permanent committee from 2002, chairman of the Bishops' Commission for Administration and Information, member of the Bishops' Commission for Liturgy and vice president of the conference. He has been chair of the ad hoc committee for the Personal Ordinariate of Our Lady of the Southern Cross since 2010. In May 2012, he was elected president of the Australian Catholic Bishops Conference for two years. He has been a member of the International Commission on English in the Liturgy since 2003 and its vice president. He took part in the Oceania Synod and ad limina visits in 1998, 2004 and 2011. In 2007, Hart expressed that he was troubled by the remarks of St Patrick's Cathedral priest Geoff Baron. During 2016, Hart urged schools to be sensitive and respectful to students who want to invite a same-sex date to school dance nights. "These are quite often emotional situations and it's very important that we always have respect for the dignity of the human being involved", he said when Fairfax asked for his response to a previously unreported case at the Academy of Mary Immaculate in Fitzroy. He was appointed a member of the Congregation for Divine Worship and the Discipline of the Sacraments. Pope Francis accepted his resignation on 29 June 2018. Hart requested a Melbourne parish priest stand down while the priest was investigated by civil authorities for allegedly violating child safety laws.
Controversies
In 2009 during a court case, Hart was accused of having told a woman to "Go to hell, bitch" when she had knocked on his door in the middle of the night in 2004. On the ABC on 14 November 2013, Hart acknowledged making the comment, then immediately asserting that he always followed the teachings of the Roman Catholic Church. He apologised for it and described it as unfortunate. In May 2013, Hart appeared at a Victorian parliamentary inquiry into child sex abuse. He commented, in regard to why it took 18 years to have a priest laicised for sexually abusing children, "Better late than never." On 15 August 2017, Hart stated that if the law was changed to require clergy to report child sexual abuse learned of during confessionals he would break the law and not report such abuse.